Cold atom interferometers are the basis for a newer class of inertial sensors. Analogous to the function of a fiber optic or ring laser gyroscope, inertial forces induce phase shifts in the quantum mechanical wave function of atoms traversing a loop in a cold atom interferometer.
For some operating parameters, cold atom inertial sensors may provide a lower update rate than desirable. In such cases, micro-electrical-mechanical systems (MEMS) inertial sensors may be used as a sort of flywheel to provide continuous output between atomic sensor readings. In this situation, the atomic inertial sensor can be used to correct bias and scale factor drift in the MEMS inertial sensor.
In order to minimize size, weight, and power, it is desirable to make the atomic inertial sensor as small as possible. Unfortunately, sensitivity scales unfavorably with reduced sensor size. A minimum atomic inertial sensor volume of approximately 6 cm3 is necessary to meet some performance metrics. However, the total volume metric for a six degree of freedom atomic inertial measurement unit (IMU) is required for some applications to be less than 20 cm3.